The present invention relates to cylindrical suction boxes and, in particular, it concerns a cylindrical suction box assembly having two or more suction chambers that operate at different suction pressures.
It is known to provide a patterning cylinder having a substantially hollow interior volume and to generate a vacuum state within the interior volume. The suction force created by the vacuum state serves to draw the fluid, generally water, used in the texturing process out of the cylinder. This process leaves the fabric with a relatively high water content requiring de-watering using a de-watering box further along the production line.
Since the now textured fabric is no longer being supported by the patterning cylinder, the air being drawn through the fabric by the suction force of the suction box will follow a path of least resistance such as through the regions where the fabric is thinnest. Therefore, the thicker areas of the fabric, where the resistance to air flow is higher, will retain more water and will require longer drying, thereby increasing production costs.
There is therefore a need for cylindrical suction box assembly having two or more suction chambers that operate at different suction pressures such that the water introduced to the interior of the suction box during the texturing process is drawn out by a low suction force and the fabric is then de-watered by a high suction force while still supported by the patterning cylinder.